I'm 39 and have not had sex in over 7 months and have been tested for STD's here's my problem. Any input would be greatly appreciated...

I had my period on August 20th. But I'm still bleeding. It almost like it only happens when I'm laying down. My lower abdomen is not real painful, just an uncomfortable feeling. Its a watery pink discharge. Its not like normal bleeding when I have my monthly. I have had bouts of very sharp pains but they go away. Also, seems like a headache almost every night. Sometimes there seems to be an odor. I just don't understand why this only seems to be happening when I lay down. My fear is its cancer. And I can't get in to see the OBGYN untill Sept. 30th... Could it be the early stages of uterine cancer? Any thoughts would greatly be appreciated!! Thank you

Also, My periods for i would say the past year have been all over the map to lasting almost two weeks, Heavy, Light, very crampy too no cramps.

Could be a polyp. Could be an infection. Could be hyperplasia.
Could be a hormonal issue.

Not very likely to be endometrial cancer, given your age; less than 5% of cases occur before 40 (I've heard, actually, that only about 2% do).
Most cases occur over the age of 50, after menopause.
Women under 40 who get endometrial cancer tend to be obese, childless, and to suffer from polycystic ovarian syndrome.
If the above characteristics don't apply to you, then you probably don't have it.
Actually, even if they do apply to you, you probably still don't have it.

You definitely have something, though, so get ye to a doctor and get it figured out.

I've got something very similar going on, actually, and I am in the same age bracket as you.
They have not managed to figure out why this is happening to me, exactly (it's been going on for a month and a half now), but they have ruled out cancer.
So don't worry too much. Just go to the doctor and get the tests you need.
I know it's scary, but you'll feel better once you rule out serious causes.
Good luck!